[6-(Benzoyl­oxy)-1,4,5-tri­hydroxy­cyclo­hex-2-en-1-yl]­methyl benzoate

The title compound, C₂₀H₂₁O₇, also known as purpuriol, was isolated for the first time from natural product sources. The cyclo­hexene ring adopts a half-chair conformation with an axially attached methyl benzoate and equatorially attached benzoyl­oxy substituents. The methyl benzoate and benzoyl­oxy groups are essentially planar. The dihedral angle between these groups is 9.2 (2)°. O—H...O intermolecular hydrogen bonds link the mol­ecules into chains along the a axis and the chains are interlinked by C—H...O hydrogen bonds and C—H...π interactions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.055
• wR factor = 0.121
• Data-to-parameter ratio = 7.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.66
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          6
PLAT480_ALERT_4_C Long H...A H-Bond Reported H7B    ..  CG1     ..       2.80 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.00
           From the CIF: _reflns_number_total               1962
           Count of symmetry unique reflns         1962
           Completeness (_total/calc)            100.00%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present           no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

[6-(benzoyloxy)-1,4,5-trihydroxycyclohex-2-en-1-yl]methyl benzoate

Crystal data

C21H20O7	Dx = 1.358 Mg m^−3
Mr = 384.37	Melting point = 422–423 K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1961 reflections
a = 5.9532 (8) Å	θ = 2.1–25.0°
b = 8.1287 (1) Å	µ = 0.10 mm^−1
c = 38.848 (5) Å	T = 293 K
V = 1879.9 (4) Å^3	Needle, colourless
Z = 4	0.41 × 0.12 × 0.08 mm
F(000) = 808

Data collection

Siemens SMART CCD area-detector diffractometer	1962 independent reflections
Radiation source: fine-focus sealed tube	1788 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.049
Detector resolution: 8.33 pixels mm^-1	θmax = 25.0°, θmin = 2.1°
ω scans	h = −7→7
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −9→9
Tmin = 0.960, Tmax = 0.992	l = −46→45
13378 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.055	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.121	H-atom parameters constrained
S = 1.20	w = 1/[σ^2(Fo^2) + (0.0518P)^2 + 0.6731P] where P = (Fo^2 + 2Fc^2)/3
1961 reflections	(Δ/σ)max < 0.001
256 parameters	Δρmax = 0.18 e Å^−3
0 restraints	Δρmin = −0.16 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.6440 (4)	1.0459 (4)	0.08018 (7)	0.0417 (7)
H1	0.5844	1.0449	0.0612	0.063*
O2	1.2085 (5)	0.6885 (3)	0.03245 (7)	0.0434 (7)
H2	1.3035	0.6391	0.0437	0.065*
O3	1.4545 (4)	1.0013 (4)	0.01369 (7)	0.0435 (7)
H3	1.5022	0.9302	0.0006	0.065*
O4	0.8602 (5)	0.9703 (4)	0.13748 (6)	0.0429 (7)
O5	1.1222 (5)	1.0358 (4)	0.17648 (7)	0.0566 (9)
O6	0.9220 (4)	0.7358 (3)	0.08749 (6)	0.0345 (6)
O7	0.6139 (5)	0.6241 (4)	0.06461 (7)	0.0506 (8)
C1	0.8836 (6)	1.0296 (5)	0.07628 (9)	0.0316 (9)
C2	0.9388 (6)	0.8611 (4)	0.06107 (9)	0.0292 (8)
H2A	0.8312	0.8363	0.0427	0.035*
C3	1.1761 (6)	0.8492 (4)	0.04667 (9)	0.0309 (8)
H3A	1.2840	0.8662	0.0654	0.037*
C4	1.2156 (6)	0.9774 (5)	0.01903 (9)	0.0352 (9)
H4	1.1485	0.9386	−0.0025	0.042*
C5	1.1180 (7)	1.1400 (5)	0.02770 (10)	0.0409 (10)
H5	1.1629	1.2308	0.0149	0.049*
C6	0.9707 (7)	1.1626 (5)	0.05267 (9)	0.0368 (9)
H6	0.9164	1.2688	0.0560	0.044*
C7	0.9839 (7)	1.0613 (5)	0.11176 (9)	0.0386 (10)
H7A	1.1402	1.0276	0.1120	0.046*
H7B	0.9774	1.1780	0.1169	0.046*
C8	0.9456 (7)	0.9682 (5)	0.16897 (10)	0.0350 (9)
C9	0.8062 (7)	0.8747 (5)	0.19388 (9)	0.0382 (10)
C10	0.8897 (8)	0.8376 (5)	0.22597 (10)	0.0474 (11)
H10	1.0288	0.8792	0.2325	0.057*
C11	0.7711 (11)	0.7398 (6)	0.24866 (11)	0.0643 (14)
H11	0.8298	0.7154	0.2703	0.077*
C12	0.5633 (11)	0.6782 (6)	0.23888 (12)	0.0655 (15)
H12	0.4836	0.6100	0.2537	0.079*
C13	0.4753 (9)	0.7180 (6)	0.20731 (12)	0.0614 (14)
H13	0.3341	0.6789	0.2012	0.074*
C14	0.5935 (7)	0.8152 (6)	0.18463 (11)	0.0472 (11)
H14	0.5326	0.8412	0.1633	0.057*
C15	0.7502 (6)	0.6309 (5)	0.08761 (9)	0.0313 (8)
C16	0.7475 (7)	0.5272 (4)	0.11869 (10)	0.0341 (9)
C17	0.9171 (8)	0.5322 (5)	0.14309 (10)	0.0419 (10)
H17	1.0410	0.6000	0.1397	0.050*
C18	0.9028 (10)	0.4374 (6)	0.17236 (11)	0.0534 (13)
H18	1.0180	0.4406	0.1885	0.064*
C19	0.7185 (10)	0.3373 (6)	0.17791 (12)	0.0599 (14)
H19	0.7082	0.2754	0.1980	0.072*
C20	0.5505 (9)	0.3296 (6)	0.15371 (13)	0.0621 (14)
H20	0.4275	0.2611	0.1572	0.075*
C21	0.5648 (8)	0.4241 (6)	0.12412 (12)	0.0522 (12)
H21	0.4511	0.4184	0.1077	0.063*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0227 (14)	0.0633 (19)	0.0391 (15)	0.0013 (14)	0.0041 (12)	0.0002 (15)
O2	0.0372 (17)	0.0405 (15)	0.0525 (17)	0.0071 (14)	−0.0147 (13)	−0.0106 (14)
O3	0.0293 (14)	0.0576 (19)	0.0435 (16)	−0.0038 (15)	0.0087 (12)	−0.0059 (14)
O4	0.0437 (16)	0.0590 (18)	0.0259 (13)	−0.0105 (15)	−0.0006 (12)	0.0037 (13)
O5	0.0472 (19)	0.077 (2)	0.0458 (17)	−0.0136 (19)	−0.0110 (15)	0.0066 (16)
O6	0.0320 (14)	0.0393 (14)	0.0323 (13)	−0.0087 (13)	−0.0085 (12)	0.0077 (12)
O7	0.0363 (16)	0.0631 (19)	0.0525 (17)	−0.0131 (16)	−0.0155 (14)	0.0083 (16)
C1	0.0240 (19)	0.038 (2)	0.0332 (19)	−0.0002 (18)	0.0011 (15)	0.0021 (18)
C2	0.0256 (19)	0.036 (2)	0.0263 (17)	−0.0030 (18)	−0.0067 (15)	0.0074 (16)
C3	0.0262 (19)	0.036 (2)	0.0306 (19)	0.0016 (18)	−0.0075 (15)	−0.0053 (17)
C4	0.0234 (19)	0.052 (2)	0.0297 (19)	−0.002 (2)	−0.0009 (16)	0.0013 (18)
C5	0.040 (2)	0.042 (2)	0.041 (2)	0.000 (2)	−0.0038 (19)	0.0133 (19)
C6	0.039 (2)	0.031 (2)	0.040 (2)	0.0062 (19)	0.0024 (19)	0.0055 (18)
C7	0.039 (2)	0.042 (2)	0.035 (2)	−0.0075 (19)	0.0007 (18)	−0.0023 (18)
C8	0.034 (2)	0.036 (2)	0.035 (2)	0.005 (2)	−0.0023 (18)	−0.0050 (18)
C9	0.046 (3)	0.036 (2)	0.032 (2)	0.008 (2)	0.0020 (18)	−0.0027 (18)
C10	0.060 (3)	0.047 (2)	0.035 (2)	0.008 (2)	−0.001 (2)	−0.001 (2)
C11	0.104 (4)	0.053 (3)	0.035 (2)	0.004 (3)	0.005 (3)	0.002 (2)
C12	0.096 (4)	0.049 (3)	0.051 (3)	−0.005 (3)	0.034 (3)	−0.001 (2)
C13	0.054 (3)	0.070 (3)	0.061 (3)	−0.002 (3)	0.020 (2)	0.003 (3)
C14	0.039 (3)	0.056 (3)	0.047 (2)	0.003 (2)	0.010 (2)	−0.002 (2)
C15	0.024 (2)	0.034 (2)	0.036 (2)	0.0015 (18)	−0.0008 (18)	−0.0042 (17)
C16	0.033 (2)	0.0265 (19)	0.042 (2)	−0.0004 (18)	0.0081 (18)	0.0025 (17)
C17	0.044 (2)	0.037 (2)	0.045 (2)	0.005 (2)	0.000 (2)	0.0008 (19)
C18	0.068 (3)	0.050 (3)	0.042 (2)	0.009 (3)	0.000 (2)	0.013 (2)
C19	0.084 (4)	0.045 (3)	0.051 (3)	0.012 (3)	0.028 (3)	0.016 (2)
C20	0.056 (3)	0.047 (3)	0.083 (4)	−0.006 (3)	0.027 (3)	0.012 (3)
C21	0.039 (3)	0.049 (3)	0.068 (3)	−0.007 (2)	0.006 (2)	0.007 (2)

Geometric parameters (Å, º)

O1—C1	1.440 (4)	C7—H7B	0.97
O1—H1	0.82	C8—C9	1.484 (6)
O2—C3	1.432 (4)	C9—C10	1.376 (5)
O2—H2	0.82	C9—C14	1.402 (6)
O3—C4	1.450 (5)	C10—C11	1.381 (6)
O3—H3	0.82	C10—H10	0.93
O4—C8	1.325 (4)	C11—C12	1.388 (8)
O4—C7	1.445 (4)	C11—H11	0.93
O5—C8	1.221 (5)	C12—C13	1.373 (7)
O6—C15	1.332 (4)	C12—H12	0.93
O6—C2	1.449 (4)	C13—C14	1.377 (6)
O7—C15	1.208 (4)	C13—H13	0.93
C1—C6	1.510 (5)	C14—H14	0.93
C1—C7	1.524 (5)	C15—C16	1.473 (5)
C1—C2	1.527 (5)	C16—C17	1.386 (6)
C2—C3	1.522 (5)	C16—C21	1.389 (6)
C2—H2A	0.98	C17—C18	1.376 (6)
C3—C4	1.515 (5)	C17—H17	0.93
C3—H3A	0.98	C18—C19	1.383 (7)
C4—C5	1.482 (6)	C18—H18	0.93
C4—H4	0.98	C19—C20	1.374 (7)
C5—C6	1.321 (5)	C19—H19	0.93
C5—H5	0.93	C20—C21	1.385 (6)
C6—H6	0.93	C20—H20	0.93
C7—H7A	0.97	C21—H21	0.93
C1—O1—H1	109.5	O5—C8—C9	123.8 (4)
C3—O2—H2	109.5	O4—C8—C9	113.2 (3)
C4—O3—H3	109.5	C10—C9—C14	118.9 (4)
C8—O4—C7	116.7 (3)	C10—C9—C8	120.1 (4)
C15—O6—C2	120.4 (3)	C14—C9—C8	121.0 (4)
O1—C1—C6	109.7 (3)	C9—C10—C11	121.3 (5)
O1—C1—C7	106.1 (3)	C9—C10—H10	119.3
C6—C1—C7	107.1 (3)	C11—C10—H10	119.3
O1—C1—C2	109.7 (3)	C10—C11—C12	119.2 (5)
C6—C1—C2	109.5 (3)	C10—C11—H11	120.4
C7—C1—C2	114.7 (3)	C12—C11—H11	120.4
O6—C2—C3	106.2 (3)	C13—C12—C11	120.0 (5)
O6—C2—C1	110.0 (3)	C13—C12—H12	120.0
C3—C2—C1	113.5 (3)	C11—C12—H12	120.0
O6—C2—H2A	109.0	C12—C13—C14	120.8 (5)
C3—C2—H2A	109.0	C12—C13—H13	119.6
C1—C2—H2A	109.0	C14—C13—H13	119.6
O2—C3—C4	109.5 (3)	C13—C14—C9	119.7 (4)
O2—C3—C2	109.0 (3)	C13—C14—H14	120.1
C4—C3—C2	111.2 (3)	C9—C14—H14	120.1
O2—C3—H3A	109.1	O7—C15—O6	122.9 (3)
C4—C3—H3A	109.1	O7—C15—C16	124.9 (4)
C2—C3—H3A	109.1	O6—C15—C16	112.2 (3)
O3—C4—C5	107.3 (3)	C17—C16—C21	119.0 (4)
O3—C4—C3	110.2 (3)	C17—C16—C15	122.4 (3)
C5—C4—C3	113.0 (3)	C21—C16—C15	118.6 (4)
O3—C4—H4	108.7	C18—C17—C16	120.2 (4)
C5—C4—H4	108.7	C18—C17—H17	119.9
C3—C4—H4	108.7	C16—C17—H17	119.9
C6—C5—C4	123.5 (4)	C17—C18—C19	120.5 (5)
C6—C5—H5	118.3	C17—C18—H18	119.8
C4—C5—H5	118.3	C19—C18—H18	119.8
C5—C6—C1	125.0 (4)	C20—C19—C18	119.8 (4)
C5—C6—H6	117.5	C20—C19—H19	120.1
C1—C6—H6	117.5	C18—C19—H19	120.1
O4—C7—C1	109.8 (3)	C19—C20—C21	119.9 (5)
O4—C7—H7A	109.7	C19—C20—H20	120.1
C1—C7—H7A	109.7	C21—C20—H20	120.1
O4—C7—H7B	109.7	C20—C21—C16	120.5 (5)
C1—C7—H7B	109.7	C20—C21—H21	119.7
H7A—C7—H7B	108.2	C16—C21—H21	119.7
O5—C8—O4	123.0 (4)
C15—O6—C2—C3	−129.9 (3)	C7—O4—C8—C9	179.0 (3)
C15—O6—C2—C1	106.8 (4)	O5—C8—C9—C10	−10.5 (6)
O1—C1—C2—O6	−77.4 (4)	O4—C8—C9—C10	169.1 (4)
C6—C1—C2—O6	162.1 (3)	O5—C8—C9—C14	173.0 (4)
C7—C1—C2—O6	41.8 (4)	O4—C8—C9—C14	−7.5 (5)
O1—C1—C2—C3	163.7 (3)	C14—C9—C10—C11	1.8 (6)
C6—C1—C2—C3	43.3 (4)	C8—C9—C10—C11	−174.8 (4)
C7—C1—C2—C3	−77.1 (4)	C9—C10—C11—C12	−0.2 (7)
O6—C2—C3—O2	60.3 (3)	C10—C11—C12—C13	−1.6 (7)
C1—C2—C3—O2	−178.7 (3)	C11—C12—C13—C14	1.8 (7)
O6—C2—C3—C4	−179.0 (3)	C12—C13—C14—C9	−0.2 (7)
C1—C2—C3—C4	−58.0 (4)	C10—C9—C14—C13	−1.6 (6)
O2—C3—C4—O3	−78.2 (4)	C8—C9—C14—C13	175.0 (4)
C2—C3—C4—O3	161.3 (3)	C2—O6—C15—O7	7.0 (5)
O2—C3—C4—C5	161.7 (3)	C2—O6—C15—C16	−172.8 (3)
C2—C3—C4—C5	41.3 (4)	O7—C15—C16—C17	175.3 (4)
O3—C4—C5—C6	−136.1 (4)	O6—C15—C16—C17	−4.9 (5)
C3—C4—C5—C6	−14.3 (5)	O7—C15—C16—C21	−6.6 (6)
C4—C5—C6—C1	1.2 (6)	O6—C15—C16—C21	173.3 (3)
O1—C1—C6—C5	−135.9 (4)	C21—C16—C17—C18	−0.6 (6)
C7—C1—C6—C5	109.3 (4)	C15—C16—C17—C18	177.5 (4)
C2—C1—C6—C5	−15.5 (5)	C16—C17—C18—C19	−0.6 (6)
C8—O4—C7—C1	171.3 (3)	C17—C18—C19—C20	1.5 (7)
O1—C1—C7—O4	46.3 (4)	C18—C19—C20—C21	−1.1 (7)
C6—C1—C7—O4	163.5 (3)	C19—C20—C21—C16	−0.2 (7)
C2—C1—C7—O4	−74.9 (4)	C17—C16—C21—C20	1.0 (6)
C7—O4—C8—O5	−1.4 (6)	C15—C16—C21—C20	−177.2 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O3^i	0.82	2.03	2.842 (4)	170
O2—H2···O7^ii	0.82	2.02	2.768 (4)	151
O3—H3···O2^iii	0.82	2.02	2.807 (4)	160
C2—H2A···O7	0.98	2.32	2.733 (5)	105
C4—H4···O7^iii	0.98	2.47	3.407 (5)	159
C11—H11···O5^iv	0.93	2.55	3.407 (5)	154
C7—H7B···Cg1^v	0.97	2.80	3.645 (4)	146

Symmetry codes: (i) x−1, y, z; (ii) x+1, y, z; (iii) x+1/2, −y+3/2, −z; (iv) −x+2, y−1/2, −z+1/2; (v) x, y+1, z.